Skip to main content
Sumo Logic

Collect Nginx Logs and Metrics for Kubernetes environments

In a Kubernetes environment, we use the Telegraf Operator, which is packaged with our Kubernetes collection. You can learn more about it here. The diagram below illustrates how data is collected from Nginx in Kubernetes environments. In the architecture shown below, there are four services that make up the metric collection pipeline: Telegraf, Prometheus, Fluentd, and FluentBit.

The first service in the pipeline is Telegraf. Telegraf collects metrics from Nginx. Note that we’re running Telegraf in each pod we want to collect metrics from as a sidecar deployment: i.e. Telegraf runs in the same pod as the containers it monitors. Telegraf uses the Nginx input plugin to obtain metrics. (For simplicity, the diagram doesn’t show the input plugins.) The injection of the Telegraf sidecar container is done by the Telegraf Operator. We also have Fluentbit that collects logs written to standard out and forwards them to FluentD, which in turn sends all the logs and metrics data to a Sumo Logic HTTP Source.

 

Follow the below instructions to set up the metric collection:

  1. Configure Metrics Collection
    1. Setup Kubernetes Collection with the Telegraf operator.
    2. Add annotations on your Nginx pods.
  2. Configure Logs Collection
    1. Configure logging in Nginx.
    2. Add labels on your Nginx pods to capture logs from standard output.
    3. Collecting Nginx Logs from a Log file.

Prerequisites

It’s assumed that you are using the latest helm chart version if not upgrade using the instructions here.

Configure Metrics Collection

This section explains the steps to collect Nginx metrics from a Kubernetes environment.

In a Kubernetes environment, we use the Telegraf Operator, which is packaged with our Kubernetes collection. You can learn more about this here. Follow the steps listed below to collect metrics from a Kubernetes environment:

  1. Setup Kubernetes Collection with the Telegraf Operator.

  2. Add annotations on your Nginx pods

On your Nginx Pods, add the following annotations:

 annotations:
    telegraf.influxdata.com/class: sumologic-prometheus
    prometheus.io/scrape: "true"
    prometheus.io/port: "9273"
    telegraf.influxdata.com/inputs: |+

[[inputs.nginx]]
  urls = ["http://IP_TO_BE_CHANGED/nginx_status"]
  response_timeout = "5s"

  [inputs.nginx.tags]
  environment="env_TO_BE_CHANGED"
  component="webserver"
  webserver_system="nginx"
  webserver_farm="<nginx_TO_BE_CHANGED>"

Enter in values for the following parameters (marked in bold above):

  • telegraf.influxdata.com/inputs - This contains the required configuration for the Telegraf Nginx Input plugin. Please refer to this doc for more information on configuring the Nginx input plugin for Telegraf. Note: As telegraf will be run as a sidecar the host should always be localhost.
    • In the input plugins section, that is : 
      • urls - An array of Nginx stub_status URI to gather stats. This can be a comma-separated list to connect to multiple Nginx servers. Please see this doc for more information on additional parameters for configuring the Nginx input plugin for Telegraf.
    • In the tags section, that is  [inputs.nginx.tags]
      • environment - This is the deployment environment where the Nginx farm identified by the value of servers resides. For example: dev, prod or qa. While this value is optional we highly recommend setting it. 
      • webserver_farm - Enter a name to identify this Nginx farm. This farm name will be shown in the Sumo Logic dashboards.  

Here’s an explanation for additional values set by this configuration that we request you please do not modify as they will cause the Sumo Logic apps to not function correctly.

  • telegraf.influxdata.com/class: sumologic-prometheus - This instructs the Telegraf operator what output to use. This should not be changed.
  • prometheus.io/scrape: "true" - This ensures our Prometheus will scrape the metrics.
  • prometheus.io/port: "9273" - This tells prometheus what ports to scrape on. This should not be changed.
  • telegraf.influxdata.com/inputs
    • In the tags section, that is [inputs.nginx.tags]
      • component: “webserver” - This value is used by Sumo Logic apps to identify application components. 
      • webserver_system: “nginx” - This value identifies the webserver system.

For all other parameters please see this doc for more properties that can be configured in the Telegraf agent globally.

  1. Sumo Logic Kubernetes collection will automatically start collecting metrics from the pods having the labels and annotations defined in the previous step. 

  2. Verify metrics in Sumo Logic.

Configure Logs Collection

This section explains the steps to collect Nginx logs from a Kubernetes environment.

  1. (Recommended Method) Add labels on your Nginx pods to capture logs from standard output.

Make sure that the logs from Nginx are sent to stdout. Follow the instructions below to capture Nginx logs from stdout on Kubernetes.

  1. Apply following labels to the Nginx pod

labels:
  environment="prod_CHANGEME"
  component="webserver"
  webserver_system="nginx"
  webserver_farm="<farm_CHANGEME>"

Please enter in values for the following parameters (marked in bold and CHANGE_ME above):

  • environment - This is the deployment environment where the Nginx farm identified by the value of servers resides. For example:- dev, prod, or QA. While this value is optional we highly recommend setting it.
  • Webserver_farm - Enter a name to identify this Nginx farm. This farm name will be shown in the Sumo Logic dashboards. If you haven’t defined a farm in Nginx, then enter ‘default’ for webserver_farm.

Here’s an explanation for additional values set by this configuration that we request you please do not modify as they will cause the Sumo Logic apps to not function correctly.

  • component: “webserver” - This value is used by Sumo Logic apps to identify application components. 
  • webserver_system: “nginx” - This value identifies the database system.

For all other parameters please see this doc for more properties that can be configured in the Telegraf agent globally.

  1. The Sumologic-Kubernetes-Collection will automatically capture the logs from stdout and will send the logs to Sumologic. For more information on deploying Sumologic-Kubernetes-Collection, visit here.

  2. Verify logs in Sumo Logic.

  • (Optional) Collecting Nginx Logs from a Log File

    Follow the steps below to capture Nginx logs from a log file on Kubernetes.

    1. Determine the location of the Nginx log file on Kubernetes. This can be determined from the nginx.conf for your nginx farm along with the mounts on the Nginx pods.
    2. Install the Sumo Logic tailing sidecar operator.
    3. Add the following annotation in addition to the existing annotations.
annotations:
  tailing-sidecar: sidecarconfig;<mount>:<path_of_nginx_log_file>/<Nginx_log_file_name>

Example:

annotations:
  tailing-sidecar: sidecarconfig;data:/var/log/nginx/error.log

  1. Make sure that the Nginx pods are running and annotations are applied by using the command: kubectl describe pod <nginx_pod_name>

  2. Sumo Logic Kubernetes collection will automatically start collecting logs from the pods having the annotations defined above. 

  3. Verify logs in Sumo Logic.

  • Add an FER to normalize the fields in Kubernetes environments

    Labels created in Kubernetes environments automatically are prefixed with pod_labels. To normalize these for our app to work, we need to create a Field Extraction Rule if not already created for Proxy Application Components. To do so:

  1. Go to Manage Data > Logs > Field Extraction Rules.

  2. Click the + Add button on the top right of the table.
    The following form appears:

  1. Enter the following options:

    1. Rule Name. Enter the name as App Observability - Webserver.
    2. Applied At. Choose Ingest Time.
    3. Scope. Select Specific Data.
    4. Scope: Enter the following keyword search expression. 
pod_labels_environment=* pod_labels_component=webserver pod_labels_webserver_farm=* pod_labels_webserver_system=*
  • Parse Expression. Enter the following parse expression.

if (!isEmpty(pod_labels_environment), pod_labels_environment, "") as environment
| pod_labels_component as component
| pod_labels_webserver_system as webserver_system
| pod_labels_webserver_farm as webserver_farm
  1. Click Save to create the rule.